Effect of substitution on corrosion inhibition properties of 2-(substituted phenyl) benzimidazole derivatives on mild steel in 1Â M HCl solution: A combined experimental and theoretical approach

Four new 2-(substituted phenyl) benzimidazole derivatives have been synthesized and their inhibiting action on the corrosion of mild steel in 1 M HCl is compared with that of 2-phenyl benzimidazole employing electrochemical and gravimetric measurements, as well as theoretical calculation. Results of the investigation show that substitution to the phenyl group attached to benzimidazole brings about obvious increase in corrosion inhibition propensity and is related to property of the substituent group as well as its position in the phenyl ring. Inhibition efficiency for all the inhibitors increases with their concentration and is retained for long time of exposure.